In many large server applications, processors along with their associated electronics (e.g., memory, disk drives, power supplies, etc.) are packaged in removable node configurations stacked within an electronics (or IT) rack or frame. In other cases, the electronics may be in fixed locations within the rack or frame. Typically, the components are cooled by air-moving in parallel airflow paths, usually front-to-back, impelled by one or more air-moving devices (e.g., fans or blowers). The power dissipation of integrated circuit chips, and the modules containing the chips, continues to increase in order to achieve increases in processor performance. This trend poses challenges at both the module and system level. In certain cases it may be possible to handle increased power dissipation within a single node by providing greater airflow, through the use of a more powerful air-moving device or by increasing the rotational speed (i.e., RPMs) of an existing air-moving device.
Conductive dust may be entrained within the airflow passing through the electronics rack. Within a data center, this conductive dust can include, for example, salt contaminants that have a deliquescent relative humidity above which the salt will absorb moisture, become wet and create ionic bridges, which may potentially cause short circuiting of one or more electronic components within the rack. For example, conductive dust can cause electrical short circuiting of closely spaced electrical features on circuit boards or other components with exposed metal traces, and thereby degrade system reliability. Dust arises from several origins, including outdoor air, industrial operations, data center air conditioners, hardware corrosion (e.g., blower fretting corrosion), etc. Most dust contains one or more of C, Si, Ca, O, Al, K, S, Cl, and sometimes Fe. The most harmful dust particles are generally high in sulfur and chlorine-bearing salts. If the dust is found to be conductive at the existing relative humidity level, then component damage may occur, and the data center might need to be cleaned and any failed system hardware replaced.